The songbird is the best developed animal model for human speech acquisition, processing and production. Human speech learning is served by specialized brain regions. This application focuses on two songbird brain regions that are analogous to components of mammalian auditory cortex: the thalamo-recipient field L2a and its projection target, the caudomedial nidopallidum (NCM), which has a response preference for conspecific vocalizations. An electrode array will record multi and single unit activity in response to various stimuli at multiple sites in field L2a and NCM in awake birds of two species (canary and zebra finch). The specific aims are: 1) Use synthetic stimuli (tones, band-passed noise, frequency and amplitude modulated stimuli) to map and compare neural response properties across regions and species. 2) Use natural and synthetic exemplars of conspecific and heterospecific vocalizations to compare response properties within NCM across species. 3) NCM selectivity for complex stimuli will be related to stimulus salience, as determined by behavioral assays in the same animals. Results will provide a detailed characterization of species-specific response properties across regions, and will help to elucidate how response preferences arise in NCM. [unreadable] [unreadable] [unreadable]